Gene Expression of Biofilm Formation lasB and rblB Genes of Acinetobacter baumannii Isolated from Wounds, Burns and Environmental Samples

Abstract

Multiple-drug-resistant infections linked to medical devices are common due to Acinetobacter baumannii's propensity to develop biofilm. The purpose of this work is to identify the MIC of Imipenem and Chalcon  and to investigate the involvement of the lasB gene in formation of biofilm by A. baumannii in order to get  better understand how these bacteria  can survive l in the hospital setting. As well as comparing the effect before and after of using the antibiotic and chalcone. A 250 samples were obtained from several locations in hospitals of Baghdad/Iraq and classified to 2 groups according to their source: 100 environmental and 150 clinical samples, obtained during October 2021-March 2022. Antibiotic resistance profile of A. baumannii isolates was confirmed by VITEK-2 system and in vitro biofilm-forming ability was evaluated by micro titer plate methods, respectively. Isolates were tested for the presence of lasB gene Forty (40) isolates of A. baumannii were subjected to examination under microscope and to diagnosis using biochemical tests. The (40) isolates identification was confirmed by the VITEK-2 system and a molecular detection according to the rplB gene, which is a necessary gene located in this genus. Antibiotic susceptibility testing was carried out on all (40) identified isolates, and the results detected those 36 isolates had Multi-Drug Resistance (MDR). This work indicated that 16 isolates from these 16 isolates carrying the rblB gene and 2 isolates from 6 carrying lasB that confirmed by molecular detection methods, and 38 isolates from these 40 isolates had the ability to form biofilm in the micro titer plate method, and this study show there is down expression of lasB with the antibiotic while down expression of this genes with chalcone. In conclusion, the presence of the lasB gene was significantly correlated with A. baumannii biofilm development. Biofilm production was also higher in multidrug-resistant than in other isolates. It was concluded the role of biofilm in the isolate’s resistance and the impact of the existence of lasB genes in formation of biofilm by A. baumannii strains, and lasB gene expression was reduced in those treated to imipenem and chalcone.